He has severe mental issues, and is not ready for sparring.

He may be sociopathic, or may be processing past trauma and projecting his past abusers onto his training partners.

BJJ is very poorly suited for processing trauma - in fact, it will make things worse. He's much better off with Aikido or Tai Chi.

He's a liability. In a good school, he would be filtered out of the system by higher ranks who regularly humiliate him. Which would only make him worse internally, and more of a danger to others or himself on the outside.

...

In my previous school, which taught modernized Aikido with some horseplay and Judo/BJJ stuff in it, the instructors kicked out a freshly released felon after he started trying to break people. They plain told him - "go do something solitary like Tai Chi, you need to process a lot of this rage, and are not yet ready to train with people".